Typical computer systems, especially computer systems using graphical user interface (GUI) systems such as Microsoft WINDOWS, are optimized for accepting user input from one or more discrete input devices such as a keyboard for entering text, and a pointing device such as a mouse with one or more buttons for driving the user interface. The ubiquitous keyboard and mouse interface provides for fast creation and modification of documents, spreadsheets, database fields, drawings, photos and the like. However, there is a significant gap in the flexibility provided by the keyboard and mouse interface as compared with the non-computer (i.e., standard) pen and paper. With the standard pen and paper, a user edits a document, writes notes in a margin, and draws pictures and other shapes and the like. In some instances, a user may prefer to use a pen to mark-up a document rather than review the document onscreen because of the ability to freely make notes outside of the confines of the keyboard and mouse interface.
Some computer systems permit a user to draw on a screen. For example, the Microsoft READER application permits one to add electronic ink (also referred to herein as “ink”) to a document. The system stores the ink and provides it to a user when requested. Other applications (for example, drawing applications as known in the art are associated with the Palm 3.x and 4.x and PocketPC operating systems) permit the capture and storage of drawings. Also, various drawing applications such as Coral Draw and photo and editing applications such as Photoshop may be used with stylus based input products, such as the Wacom tablet product. These drawings include other properties associated with the ink strokes used to make up the drawings. For instance, line width and color may be stored with the ink. One goal of these systems is to replicate the look and feel of physical ink being applied to a piece of paper. However, physical ink on paper may have significant amounts of information not captured by the electronic collection of a coordinates and connecting line segments. Some of this information may include the thickness of the pen tip used (as seen through the width of the physical ink) or angle of the pen to the paper, the shape of the pen tip, the speed at which the ink was deposited, and the like.
Another problem has arisen with electronic ink. It has been considered part of the application in which it is written. This leads to a fundamental inability to provide the richness of electronic ink to other applications or environments. While text may be ported between a variety of application (through use, for example, of a clipboard), ink fails to have this ability of being able to interact with the ink. For example, one could not create an image of a figure eight, copy and paste the created image into a document by means of the clipboard, and then make the ink bold. One difficulty is the non-portability of the image between applications.